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| #1019752 (Received by flhurricane at: 11:12 AM 03.Oct.2020) TCDAT5 Tropical Storm Gamma Discussion Number 5 NWS National Hurricane Center Miami FL AL252020 1000 AM CDT Sat Oct 03 2020 Observations from both the Air Force and NOAA Hurricane Hunters indicate that Gamma has continued to strengthen this morning. The cloud pattern has continued to become better organized, with an eye trying to become evident on high-resolution satellite images from the GOES-16 mesoscale sectors. Flight-level and SFMR-observed surface winds from the aircraft support an intensity of 60 kt, and the storm could strengthen a little more as long as the center remains over water. Since Gamma will be near or at hurricane intensity when it makes landfall later today, the government of Mexico has issued a Hurricane Warning for a portion of the northeastern Yucatan Peninsula. Gamma should weaken some while it moves over land tonight. Some re-intensification is likely after the center moves into the southern Gulf of Mexico. However, the numerical guidance does not show much strengthening during the next few days, possibly due to the influence of drier air and/or the interaction with another area of low pressure to the east of Gamma. The official intensity forecast is near or above the model consensus. Gamma continues northwestward at near 8 kt. The cyclone is expected to turn north-northwestward and move through a break in the subtropical ridge through 36 hours or so. Thereafter, a trough to the north moves eastward, bypassing Gamma, and later in the forecast period a ridge builds weakly over the Gulf of Mexico. This should cause the cyclone to turn toward the west and southwest. The official track forecast is close to the multi-model consensus, TVCN. Although Gamma has strengthened, its biggest threat continues to be torrential rains, flooding, and mudslides especially near and over mountainous terrain. KEY MESSAGES: 1. Gamma is expected to produce heavy rainfall for several days over portions of southeastern Mexico, the Yucatan Peninsula, Central America, and far western Cuba. This rainfall could result in life-threatening flash flooding and mudslides, particularly in the mountainous regions of southeastern Mexico and Central America. 2. Gamma is very near hurricane strength and will be near or at hurricane intensity when the center moves inland over the Yucatan Peninsula later today. A Hurricane Warning is now in effect for portions of the east coast of the Yucatan Peninsula, where tropical storm conditions are already occurring. Tropical storm conditions are expected along the north coast of the Yucatan Peninsula within the Tropical Storm Warning area later today and on Sunday. FORECAST POSITIONS AND MAX WINDS INIT 03/1500Z 20.0N 87.3W 60 KT 70 MPH 12H 04/0000Z 20.8N 87.8W 55 KT 65 MPH...INLAND 24H 04/1200Z 21.8N 88.1W 40 KT 45 MPH...OVER WATER 36H 05/0000Z 22.2N 88.3W 40 KT 45 MPH 48H 05/1200Z 22.3N 88.8W 45 KT 50 MPH 60H 06/0000Z 22.1N 89.7W 50 KT 60 MPH 72H 06/1200Z 22.0N 91.0W 50 KT 60 MPH 96H 07/1200Z 21.0N 92.5W 45 KT 50 MPH 120H 08/1200Z 20.0N 93.5W 40 KT 45 MPH $$ Forecaster Pasch |